Shaun H Posted April 18, 2006 Report Share Posted April 18, 2006 I have a water bleed in my maggie but over time I seem to have lost fluid from the system. This means that I now have the TPA all the way in but the slaves are only a tiny bit pushed out. There's definitely no air in the system as the brake is solid once it hits the rim. All it needs (I think) is more fluid in the system.Could anyone explain how I can get more fluid in there without rebleeding? Don't understand these closed systems :$ Gimme a disc anyday! Quote Link to comment Share on other sites More sharing options...
flipkickbs Posted April 18, 2006 Report Share Posted April 18, 2006 Back off your tpa completely, turn your lever completely upside down on the bars so that the grub screw next to the hose on your lever body is at the top of the system. Once you've done that, get a bottle of water (any bottle will do) fill it up, then take out the grub screw on your lever body. Pull the lever all the way in and LEAVE IT PULLED IN!! Then take the bottle of water and start pouring it into the grub screw hole consistently so there is no break in the water being put into it, while doing this, release the lever very slowly so that it sucks in the water. Once the lever is all the way out, gently pour a bit of water to completely fill the grub screw hole, then put the grub screw back in. The system is then topped up, and you can adjust your tpa accordingly Ian Quote Link to comment Share on other sites More sharing options...
Shaun H Posted April 18, 2006 Author Report Share Posted April 18, 2006 What if I submerged the lever in a bucket instead of pouring? It'd be hard to make sure it's the highest part of the system but as it would be completely submerged would it matter? I'd have thought it would be better than pouring as there'd be much less chance of air entering the system? Quote Link to comment Share on other sites More sharing options...
flipkickbs Posted April 19, 2006 Report Share Posted April 19, 2006 Well i said it that way as then you don't even need to take the lever off the bars, and as said, if you pour consistently, then there will be no air getting in. Your brake will only be as good as YOU bleed it. I've topped up my brake using that method numerous times, and its fine for me Ian Quote Link to comment Share on other sites More sharing options...
downhill_rob2@hotmail.com Posted April 19, 2006 Report Share Posted April 19, 2006 Well i said it that way as then you don't even need to take the lever off the bars, and as said, if you pour consistently, then there will be no air getting in. Your brake will only be as good as YOU bleed it. I've topped up my brake using that method numerous times, and its fine for me Ian**sigh**Do you have a bleed kit? (shaun)ifso....Take the bleed bolt from the slavce cylinder (next to pads) out, then put your hose with the suringe in. fill sutinge with water, then push water into the system (making sure that the grub screw at the lever is STILL IN! (dont take it out) this wil push the piston in the lever back out (good thing) then take the grub screw from the lever out, and bleed as normal...MAKE SURE YOUR TPA IS FULLY OFF WHEN DOING THIS....Your brake will be as good as its ever been P.S, if your pads are only moving a little bit, then you HAVE got air in the system, that "solid" feeling is the brake piston in the lever bottoming out, so it wont push the pads any thurther. thats why you need to blast some water into the brake with the grub screw still in the lever, to push the piston back out so it hits the lever blade.The piston gets stuck when its pushed too far in (what you have done with using too much TPA)Try that, and then tell me if its worked Quote Link to comment Share on other sites More sharing options...
Shaun H Posted April 19, 2006 Author Report Share Posted April 19, 2006 **sigh**Do you have a bleed kit? (shaun)ifso....Take the bleed bolt from the slavce cylinder (next to pads) out, then put your hose with the suringe in. fill sutinge with water, then push water into the system (making sure that the grub screw at the lever is STILL IN! (dont take it out) this wil push the piston in the lever back out (good thing) then take the grub screw from the lever out, and bleed as normal...MAKE SURE YOUR TPA IS FULLY OFF WHEN DOING THIS....Your brake will be as good as its ever been P.S, if your pads are only moving a little bit, then you HAVE got air in the system, that "solid" feeling is the brake piston in the lever bottoming out, so it wont push the pads any thurther. thats why you need to blast some water into the brake with the grub screw still in the lever, to push the piston back out so it hits the lever blade.The piston gets stuck when its pushed too far in (what you have done with using too much TPA)Try that, and then tell me if its worked There's definitely no air in the system. The pistons are not bottoming out there's simply not enough fluid in the system meaning I have to run the TPA all the way in. The brake doesn't lack power and it's solid when the pads are hitting the rim not before.I've thought of a quick fix which might work - if I submerge the lever, undo the grub screw then undo the TPA will it suck in more fluid? I'm assuming it must do as it can't take any fluid from the slaves they're already backed all the way in. Just an idea... Quote Link to comment Share on other sites More sharing options...
oakley Posted April 19, 2006 Report Share Posted April 19, 2006 If there is no air in the system mate, how can you put more water in it!!! if tyhere is room to fit more water there is air in it and if there is no air like you say there is no room for more water!!!joE! Quote Link to comment Share on other sites More sharing options...
Shaun H Posted April 19, 2006 Author Report Share Posted April 19, 2006 If there is no air in the system mate, how can you put more water in it!!! if tyhere is room to fit more water there is air in it and if there is no air like you say there is no room for more water!!!joE!If I wound the TPA all the way out I'd be creating a sort of vacuum if you get me. Because there isn't enough water in there I've had to wind the TPA all the way in to get decent lever travel. If there was air in the system I'm sure it'd be much more apparent and my lever would be like a sponge.I can put more water in it if I wind out the TPA, as this will be retracting the lever piston whilst the slaves cannot retract anymore as they are already fully in.I can't think of it being anything other than there not being enough fluid in the brake. Quote Link to comment Share on other sites More sharing options...
ScotchDave Posted April 19, 2006 Report Share Posted April 19, 2006 If your going to try to do the submersion thing make sure you submerge it, take out the grub screw and THEN wind the TPA in. Quote Link to comment Share on other sites More sharing options...
downhill_rob2@hotmail.com Posted April 19, 2006 Report Share Posted April 19, 2006 You didnt get what i meant...Is that solid feeling when the pads hit the rim VERY solid and it doesnt want to pull in even 1 more mm?If it is, then the piston IS bottoming out... if your riding with the TPA right in, then the piston in the lever IS bottoming out, the brakes are designed like that...see when you fully unscrew the TPA, does the lever pull asif its a V-brake lever without a cable in, then it suddenly hit something, then the pads move?If it does, your piston is stuck in/on slightly.This is due to riding with air in your system, so you have screwed your TPA right in, so that the piston gets pushed so far in, there isnt enough power in the spring to push it back out.so... do what i said before... take bleed bolt from slave cylinder out, then push some fluid into it using a suringe. this will push more fluid into the system, pushing the pads against the rim, pushing the piston at the lever out.Then rebleed.Try that, then tell me if it works... il bet on it that it does work... Quote Link to comment Share on other sites More sharing options...
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